JPH0441921A - Control device of cooling fan - Google Patents

Abstract

PURPOSE:To achieve noise reduction by setting the driving condition of a cooling fan of a radiator changeable to plural stages based on the parameters related to the operating conditions of an engine, and setting forcibly the cooling fan to the maximum capacity driving condition when the temperature of cooling water is kept above the predetermined high temperature for more than the predetermined time. CONSTITUTION:A switching means M1 of the driving condition of a cooling fan is provided, which changes the driving condition of a cooling fan of a radiator to plural stages based on the parameters related to the operating conditions of an engine. A time counting means M2 for the high temperature condition is provided which measures the total consecutive time of excess in the condition when the temperature of cooling water exceeds the predetermined value. When the measured time obtained through the counting means M2 for the high temperature condition exceeds the predetermined value, the driving condition of the cooling fan is forcibly set to the maximum capacity driving condition irrespective of the above-mentioned parameters, then the switching means M1 of the cooling fan driving condition is controlled by means of the forced control means M3 of the maximum capacity driving so as to hold the maximum capacity driving condition until the temperature of cooling water becomes below the above-mentioned predetermined value of the high temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cooling fan control device that switches and drives a radiator cooling fan in multiple stages.

[Prior Art] Conventionally, in an engine cooling control system of a vehicle such as an automobile, the drive state of a radiator cooling fan is changed depending on the temperature of the cooling water to prevent overheating.

To switch the driving state of the cooling fan, for example, as disclosed in Japanese Utility Model Application Publication No. 57-193015, a fan motor drive whose output signal changes according to the temperature of engine cooling water detected by a water temperature sensor is required. A circuit that changes the speed of an electric fan for a radiator in a stepless or stepwise manner, or a cooling water temperature switch made of wax or the like, as disclosed in Japanese Patent Laid-Open No. 58-192917, and an energizing path for the motor. Some devices have multiple stages of contacts forming the cooling water temperature switch, and select the contact points of the cooling water temperature switch according to the outside temperature to switch the cooling water temperature at which the cooling fan motor is controlled on and off.

[Problems to be Solved by the Invention] By the way, when driving the cooling fan, it is desirable to drive the cooling fan at as low a rotation speed as possible in consideration of the margin against engine overload. If the cooling water temperature rises above the predetermined high temperature setting value,
Always driving the cooling fan at the maximum rotation speed not only increases the noise level but also wastes energy.

In other words, even if the cooling water temperature exceeds the high temperature setting value, it is not necessarily necessary to drive the cooling fan at the maximum rotation speed depending on the operating state of the load on the engine such as the air conditioner. When the driving state of the cooling fan is switched, a contradiction arises in that countermeasures against overheating are not necessarily perfect under extreme operating conditions.

[Object of the Invention] The present invention has been made in view of the above circumstances, and is capable of precisely controlling the driving state of the cooling fan according to the operating state of the engine, and preventing overheating under all operating states. The purpose of the present invention is to provide a cooling fan control device that can control the cooling fan.

[Means for Solving the Problems] In order to achieve the above object, the cooling fan control device according to the present invention, as shown in FIG. A cooling fan driving state switching means M1 that switches to multiple stages; a high temperature state clocking means M2 that measures the duration of the state in which the engine cooling water temperature exceeds the high temperature set value when it exceeds the high temperature set value; When the time measured by the clocking means M2 exceeds the set time, the cooling fan drive state switching means M1 is forced to set the cooling fan drive state to the maximum capacity drive state regardless of the above parameters, and the drive state of the cooling fan is forced to the maximum capacity drive state. Maximum capacity drive forcing means M for maintaining the state until the cooling water temperature becomes equal to or lower than the high temperature setting value.
3.

[Function] In the cooling fan control device having the above configuration, the cooling fan drive state switching means M1 switches and controls the cooling fan drive state of the radiator in multiple stages based on parameters related to the operating state of the engine.

When the engine cooling water temperature exceeds the high temperature setting value,
The duration of the state in which the high temperature setting value is exceeded is counted by the high temperature state clocking means M2, and when this timer exceeds the set time, the driving state of the cooling fan is changed by the maximum capacity drive forcing means M3 regardless of the above parameters. It is forcibly driven to maximum capacity and maintained.

After that, when the cooling water temperature falls below the high temperature setting value,
The cooling fan driving state is again controlled to be switched by the switching means M1 based on the parameters.

[Embodiments of the invention] Hereinafter, the present invention will be described in detail with reference to the drawings.

Figure 2 and the following diagrams show one embodiment of the present invention. Figure 2 is a schematic diagram showing the engine cooling control system, Figure 3 is an explanatory diagram showing the operating mode of the cooling fan, and Figure 4 is the initial stage of the cooling fan. Flowchart showing the control procedure, FIG. 5 is a flowchart showing the cooling fan control procedure, FIG. 6 is an explanatory diagram showing the cooling fan control conditions, and FIG. 7 is an explanation showing the switching hysteresis of the cooling fan driving state depending on the cooling water temperature. 8 are explanatory diagrams showing switching hysteresis of the cooling fan driving state depending on vehicle speed.

(Configuration of Cooling Control System) In FIG. 2, reference numeral 1 is an engine body, and the figure shows a horizontally opposed engine. Cylinder block 2 and left and right bank cylinder heads 3 of this engine body 1
A water jacket 1-4 is formed, and the discharge side of the water pump 6 is connected to the cooling water inlet of the water jacket 4.

Furthermore, a thermostat 7 is disposed on the suction side of the water pump 6, and this thermostat? -7 is connected to the radiator 9 via a cooling water passage 8, and the cooling water of the radiator 9 is sent from below the engine body 1 to the water jacket 4 by the water pump 6, and the cooling water is sent to the water jacket 4 from below the engine body 1. The cooling water system is a down-flow one-type cooling water system in which the heat-exchanged cooling water is returned to the radiator 9 from above the engine main body 1.

Also, from the water jacket 4 to the idle control valve 1
0, a passage 12 passing through the throttle body 11 and a heater passage 14 passing from the water jacket 4 to the heater 13 merge into a circulation passage 15, and this circulation passage 15 is connected to the outlet side of the thermostat 7 (water pump 6). Furthermore, the cooling water outlet side of the water jacket 4 is connected to the radiator 9 via a return passage 16.

Also, a main cooling fan 1 is provided opposite the radiator 9.
7a and a sub-cooling fan 18a are provided, and each of the main cooling fan 17a and the sub-cooling fan 18a has a fan motor 17b.

18b. Furthermore, the radiator 9
An air conditioner condenser 9a is disposed on the side of the sub-cooling fan 18a.

Incidentally, reference numeral 9b is a reserve tank that stores cooling water that overflows from the radiator 9.

The fan motors 17b and 18b are composed of multi-turn coil motors, and each of the multi-turn coils has a first . A relay unit 19 consisting of second control relays RYI and RY2 is connected to a power supply +V via each relay contact.

As shown in FIG. 3, the operating modes (main, sub-fan mode) of the main cooling fan 17a and the sub-cooling fan 18a are as follows. 2nd control relay RYI,
Stops when both RY2 relay contacts are OFF (0FF)
mode, and the relay contact of the first control relay RY1 is OFF.
Low speed ([0) mode when the relay contact of the second control relay RY2 is ON in FF, the relay contact of the first control relay RY1 is ON and the relay contact of the second control relay RY2 is OFF.
When , medium speed (Hi) mode, 1st. 2nd control relay RY
There are four stages in which the high speed (old) mode is entered when relay contacts 1 and RY2 are both ON, and the motor rotational speed is switched to achieve these four stages of operation mode.

On the other hand, reference numeral 20 is a control unit (ECU), and this ECU 20 includes a CPU 21, a ROM 22, an RA
It is constituted by a microcomputer consisting of M23 and I10 interfaces 24.

A vehicle speed sensor 25, an air conditioner switch 26, a refrigerant pressure switch 27, and a cooling water temperature sensor 28 facing the cooling water outlet side of the water jacket 4 are connected to the input port of the I10 interface 24. A relay drive circuit 28 consisting of NPN transistors TR1 and TR2 is connected to the output port 1024.

The collectors of these transistors TRI and TR2 are connected to the first transistors mentioned above. Second control relay RY1. Each coil of RY2 is connected and each emitter is grounded.

The refrigerant pressure switch 27 is set to be turned on when the refrigerant pressure of the air conditioner exceeds a predetermined value, that is, when the load of the air conditioner is high.

(Operation) Next, the operation of the embodiment with the above configuration will be explained according to the flowcharts of FIGS. 4 and 5.

(Cooling Fan Control Initialization) The flowchart shown in FIG. 4 is an initialization program for cooling fan control, which is executed only for the first time when the ECU 20 is powered on.

First, in step 5101, the water temperature condition determination flag F[^ is set to indicate that the cooling water temperature T14 is higher than the high temperature set value TWSET (TW > TWSET).
Clear G1 FLAG1←0), step 510
2, the vehicle speed S is higher than the set vehicle speed S SET (S>
Clear the vehicle speed condition determination flag FLAG2, which indicates that the flag is set (FLAG2←
0).

Next, the process advances to step 5103 to clear the cooling fan high speed mode designation flag FLAG3, which designates the main and sub fan modes as high speed (old) mode. FLAG3←0
), in step 5104, both transistors TR1 and TR2 of the relay drive circuit 28 are turned off, and the first . By turning off both second control relays RYI and RY2, the main and sub fan modes are set to stop (0FF) mode, and the program ends.

(Cooling Fan Control) When the above initialization is completed, the control program shown in the flowchart of FIG. 5 is interruptedly activated at predetermined time intervals to control the operation of the cooling fans 17a and 18a.

First, in step 5201, the cooling water temperature Tw, vehicle speed S, air conditioner switch status, and refrigerant pressure switch status are read.
In step 5202, refer to the water temperature condition determination flag [[^G1, and when FLAG1=O, that is, when the cooling fan control routine is performed for the first time, or when the cooling water temperature is on the low temperature side in the previous routine, proceed to step 5203.
The first high temperature setting value TW stored in the ROM 22 in advance
SETO (for example, 95°C) is compared with the cooling water temperature TW read in step 3201 above, and TW < TW
When , the process advances to step 5205 and TW≧T WSE
When it is TO, the process advances to step 8208.

On the other hand, when FLAGl = 1 in step 5202, that is, when the cooling water temperature Tw was on the high temperature side in the previous routine, the process advances to step 5204, and the ROM 2
The second high temperature set value T WSETO− stored in 2
A, that is, the value obtained by subtracting the predetermined value A (e.g., equivalent to 1 bit of the minimum resolution) from the first set value T WSETO, and the cooling water temperature T read in step 3201 above.
When TW<Tll5ETO-A, the process proceeds to step 5205, and when TW≧T5ETO-A, the process proceeds to step 8208.

As a result, as shown in FIG. 7, hysteresis is provided in switching the operation of the cooling fans 17a and 18a based on the cooling water temperature determination, thereby preventing control hunting.

If it is determined in step 5203 that TW < TWSETO, or in step 5204 that TW < 5ETO-A, that is, the cooling water temperature T- is on the low temperature side, in steps 8205 to 3207, the water temperature condition determination flag FLAG1, Count value C0IJN of a counter for measuring the duration of the state in which the cooling water temperature T- is on the high temperature side
■, and G3 to the cooling fan high speed mode designation flag FL.
Clear FLAG1←O, C0UNT←0,
FLAG3←0), proceed to step 5213.

On the other hand, in step 5203 above, T-≧TWSET(1,
Alternatively, in step 5204, T−≧TenSE■0−A
In other words, if the cooling water temperature T@ is on the high temperature side, the water temperature condition determination flag F[A
Set Gl FLAGI←1), step 520
Proceed to 9 and set the cooling fan high speed mode designation flag FLAG3.
Determine the state of.

Cooling fan high speed mode designation flag F[^G3 is FLAG
If 3=1, that is, the high-speed (Hi) mode has already been specified, step 5212 is yambed, and the FLAG
When 3=0, step 5209 to step 521
Go to 0.

In step 5210, the counter is counted up (COUNT ←C0UNT + 1).Step 52
Proceed to step 11 and check whether the count value C0IJNT of the counter exceeds the set value C0tlNTSET, that is, whether the cooling water temperature T- is TW≧TWSETO or T-≧14
It is determined whether the high temperature state of sETO-A continues for a set time.

Above Stella 7' 3211 TE C0UNT < C0U
NTSET(7),! : Then, proceed to step 5207, clear the cooling fan high speed mode designation flag FLAG3 (FLAG3←O), proceed to step 5213, and select C.
When 0UNT≧C0UNTSET, step 52
Please set the cooling fan high speed mode designation flag FLAG3 in 12 (FLAG3-1), Stella 75213
Proceed to.

In step 5213, the vehicle speed condition determination flag FLAG2
When FLAG2 = 0, that is, when the cooling fan control routine is performed for the first time, or when the vehicle speed S was stopped in the previous routine, or when the vehicle speed S was on the low vehicle speed side, the process proceeds to step 5214, and the above-mentioned procedure is performed in advance. ROM
The first vehicle speed setting value S5ETO stored in 22 (for example, 10 m/h) is compared with the current vehicle speed S, and when S<S5ETO, the process advances to step 8216 and the vehicle speed condition determination flag FLAG2 is set. Clear (FL
AG2←0) Proceed to step 8218, S ≧ S 5E
When TO, step 5214 to step 52 are performed.
Proceed to step 17 to set the vehicle speed condition determination flag FLAG2 (AG2←1), and proceed to step 5218.

On the other hand, when FLAG2 = l in the above step 5213, that is, when the vehicle was in the running state in the previous routine, the process advances to step 5215, and the second vehicle speed setting value S5ETO, -B, which is stored in advance in the ROM 22, is set as above. A value obtained by subtracting a predetermined value B (e.g., equivalent to 1 bit of minimum resolution) from the first vehicle speed setting value S5ETO;
The vehicle speed is compared with the current vehicle speed S, and when S<S5ETO-B, the process advances to step 8216, and S≧S5ETO-
When the result is B, the process advances to step 5217.

As a result, as shown in FIG. 8, hysteresis is provided in the vehicle speed condition to prevent control hunting, and step 821
Proceed to step 8.

In step 8218, the state of the cooling fan high speed mode designation flag FLAG3 is determined, and in the case of F[8G3-1, the process proceeds to step 5230, where both transistors TRI and TR2 of the relay drive circuit 28 are turned on and the first,
Second control relay RY1. By turning on both RY2, the main and sub fan modes are set to high speed (old) mode and the routine is exited.

Therefore, if the cooling water temperature T@ exceeds the high temperature setting value for a set period of time or more, the high speed (old) mode is immediately set.

On the other hand, when FLAG3=O in step 5218, the process proceeds to step 5219 and subsequent steps, and the cooling fans 17a and 18a are optimally controlled according to each condition.

In step 5219, the state of the air conditioner switch is determined, and if the air conditioner switch 26 is OFF, step 5219 is performed.
Proceed to step 220, and from the water temperature TW state, the cooling fan 17a,
The operation mode of 18a is set to medium speed (Hl) mode and stop (O
FF) mode.

That is, in step 5220, the water temperature condition determination flag FL
Determine the state of AG1, and when F[8G1=1, the cooling water temperature Tw is on the high temperature side, so proceed to step 5229, turn on the transistor TRI of the relay drive circuit 28, and turn on the first control relay RYI. At the same time, the transistor TR2 is turned off, the second control relay RY2 is turned off, the main and sub fan modes are set to medium speed (Hi) mode, and the routine is exited, and when FLAGI = 0,
Since the cooling water, ITH, is on the low temperature side and there is plenty of room for overheating, the process proceeds to step 5221, where the transistor TRI of the relay drive circuit 28 is removed.

1st with TI'12 both OFF. 2nd control relay R
By turning off both Y1 and RY2, the main and sub fan modes are turned off (OFF) to prevent noise caused by the cooling fan.

On the other hand, when the air conditioner switch 26 is ON and the air conditioner is in operation, steps 5219 to 522 are performed.
2, the vehicle running state is determined by referring to the vehicle speed condition determination flag FLAG2.

When FLAG2 = O and the vehicle is stopped or at low speed, steps 5223 and 5224 set the main and sub fan modes to O) mode for low speed or medium speed based on the cooling water temperature T- and the state of the refrigerant pressure switch 27. 04i) Decide whether to set the mode.

In the above step 5222, when FLAG2 = O, the process proceeds to step 5223 and the water temperature condition determination flag FLAG is set.
1, when FLAGI = 1 and the cooling water temperature TW is on the high temperature side, steps 5223 to 52 are performed.
Go to 29 and set main and sub fan mode to medium speed (Hi)
Exit the routine as mode.

Further, in step 5223, if FLAG1=O and the cooling water temperature TW is on the low temperature side, the process advances to step 5224,
The state of the refrigerant pressure switch 27 is determined, and when the refrigerant pressure switch 27 is ON and the load of the air conditioner is high, the step 522 is performed in order to improve the heat dissipation by the capacitor 9a.
4 to step 5229, the main and sub fan modes are set to medium speed (Hi) mode, and the routine is exited. When the refrigerant pressure switch 27 is OFF and the load on the air conditioner is low, the process proceeds from step 5224 to step 8228, where the relay drive circuit 28 The transistor TR1 is turned off to turn off the first control relay RYI, and the transistor TR2 is turned on to turn on the second control relay RY2, and the main and sub fan modes are set to low speed ([0) mode and the routine is exited.

On the other hand, when it is determined in step 5222 that the vehicle is running with FLAG2 = 1, the process proceeds to step 5225 and subsequent steps, and the operating mode of the cooling fan is set to low speed (Lo) mode based on the cooling water temperature T- and the state of the refrigerant pressure switch 27. , switch to medium speed (Hi) mode or high speed (old) mode.

That is, in step 5225, the state of the water temperature condition determination flag FLAGI is determined, and when FLAG1=0 and the cooling water temperature T- is on the low temperature side, the process proceeds to step 5226, where the state of the refrigerant pressure switch 27 is determined, and the refrigerant pressure switch is When the refrigerant pressure switch 27 is OFF, the process advances to step 8228, where the main and sub fan modes are set to low speed ([0) mode, and the routine exits. When the refrigerant pressure switch 27 is ON, the process advances from step 8226 to step 5229, where the main and sub fan modes are set to low speed ([0) mode. The mode is set to medium speed (Hi) mode and the routine is exited.

Further, in step 5225, when the cooling water temperature T- of FLAGl = 1 is on the high temperature side, the process proceeds to step 5227 to determine the state of the refrigerant pressure switch 27, and when the refrigerant pressure switch 27 is OFF, that is, the load of the air conditioner is is relatively low but the cooling water temperature TW is high, the process advances to step 5229 and the main and sub fan modes are set to medium speed (H
i) Exit the routine as mode.

When the refrigerant pressure switch 27 is ON in step 5227, that is, when the vehicle is running and the air conditioner is operating, the engine load is relatively large and the air conditioner load is also high.
Since the cooling water temperature TW is on the high temperature side, the process proceeds to step 5230, sets the main and sub fan modes to high speed (old) mode, and exits the routine.

In this way, the operating mode of the cooling fan is precisely controlled according to the conditions shown in Figure 6, preventing energy waste and reducing noise, and moreover, the cooling water temperature T- exceeds the high temperature setting value and a set time elapses. In this case, the cooling fan is unconditionally set to the high-speed mode, which is the maximum capacity operating state.

This makes it possible to reliably prevent an overflow no matter what operating state the engine is in.

[Effects of the Invention] As explained above, according to the present invention, the radiator cooling fan drive state is switched to multiple stages based on parameters related to the engine operating state, and when the engine cooling water temperature exceeds the high temperature set value, If the state continues beyond the set time, the operating state of the cooling fan is forced to the maximum capacity operating state regardless of the parameters, and is maintained until the cooling water temperature becomes equal to or less than the high temperature setting value.

Therefore, the cooling fan can be precisely controlled according to the operating state of the engine, noise reduction can be achieved, and energy waste can be prevented.
Moreover, excellent effects such as being able to prevent overloading are achieved under all operating conditions.

[Brief explanation of drawings]

Figure 1 is a claim correspondence diagram showing the basic configuration of the present invention, Figure 2 is a claim correspondence diagram showing the basic configuration of the present invention.
The following figures show one embodiment of the present invention, Fig. 2 is a schematic diagram showing the engine cooling control system, Fig. 3 is an explanatory diagram showing the operating mode of the cooling fan, and Fig. 4 is the initial control procedure of the cooling fan. 5 is a flowchart showing the cooling fan control procedure, FIG. 6 is an explanatory diagram showing the cooling fan control conditions, and FIG. 7 is an explanatory diagram showing the hysteresis of switching the cooling fan drive state depending on the cooling water temperature. FIG. 8 is an explanatory diagram showing the switching hysteresis of the cooling fan driving state depending on the vehicle speed. Ml... Cooling fan drive state switching means M2... High temperature state clocking means M3... Maximum capacity drive forcing means 3 Fig. 4

Claims (1)

[Scope of Claims] Cooling fan drive state switching means for switching a cooling fan drive state of a radiator into multiple stages based on a parameter related to an engine operating state; a high-temperature state timer for measuring the duration of the state exceeding a set value; and when the time measured by the high-temperature state timer exceeds the set time, the drive state of the cooling fan is sent to the cooling fan drive state switching means; a maximum capacity drive force means for forcibly bringing the unit into a maximum capacity drive state regardless of the parameters, and maintaining this maximum capacity drive state until the cooling water temperature falls below the high temperature set value. Fan control device.